The concentrations of 238U, 232Th, and 40K in water from Lake Bosumtwi and bore-holes in selected
towns around the Bosumtwi basin of the Ashanti region of Ghana have been determined. The concentrations
were determined for water samples from 24 boreholes and 12 points across the lake using a High-Purity
Germanium (HPGe) (γ-ray spectrometry. The water samples from the lake were found to contain acceptable
levels of radionuclides with mean activity concentrations of 7.9, 89.7 and 0.6 mBq/L for 238U, 40K, and 232Th,
respectively. The water samples from the boreholes recorded mean activity concentrations of 7.7, 85.5, and 3.3
mBq/L for 238U, 40K and 232Th, respectively. The annual effective dose calculated for the lake varied from 0.244
to 1.121 μSv with an average of 0.763 μSv and that calculated for the boreholes varied from 0.296 to 2.173 μSv
with an average of 1.166 μSv. The radionuclides concentrations in water from the bore-holes and that of the
lake, which serve as sources of water supply to the surrounding communities are negligible and pose no
radiological hazards to the public.